Disclosed herein, is a bi-functional allosteric protein-drug molecule comprising a targeting moiety, one or more biological binding domains, and one or more therapeutic agents, wherein the therapeutic agent is allosterically bound to the biological binding domain. Also described herein, are methods of incorporating a bi-functional allosteric protein-drug molecule comprising a targeting moiety, one or more biological binding domains that captures the therapeutic agent without the formation of a chemical bond, and one or more therapeutic agents; physiologically acceptable compositions including them; and methods of administering the bi-functional allosteric protein-drug molecule to patients for the treatment of cancer.